This is the first boss of the Mythwright Gambit raid wing. His encounter starts at the start of the raid, there is no pre-event.
Firstly, the map looks like a half-circle devided in 4 quadrants. The boss will spawn in the hole of the inner circle.
A picture of the map, with the quadrants numbered, looks as follows: https://gyazo.com/fc838008261bbd66f8e8bdef5ee26d97
Secondly, this fight has 4 special roles.
These roles only matter for the collection phases.
They are the following:
The rest of the group has a dps phase during this collection phase, so "optimally" it's done by the support players.
Not mandatory though, everyone can do it.
Thirdly, know that this fight favours power over condition very much. Condition damage classes should absolutly swap to a power build if possible.
Lastly, there are 2 kinds of adds during this fight which spawn on specific points in the fight. These are conjured swords and conjured shields.
Conjured swords can be killed fairly fast, conjured shields need to be CC'd first. Also know that these shields can not be pulled in.
If a sword and a shield merge, they become a conjured warrior, which can do massive damage to the group. Therefore it's important that we properly kill these adds when they appear.
When a conjured sword is killed, he will drop a "sword pickup". When a shield is killed, he will drop a "shield pickup".
A sword pickup is used to:
1) damage the boss
2) remove armor from the boss
3) break the shield of the boss if he has it
4) cc the shields
A shield pickup is used to:
1) reduce damage from thunderclaps
2) reduce damage from the rubble walls.
These pickups manifest as a special action key ability, and also show as a symbol above your head.
When to use these pickups is explained below.
The fight itself consists of a pattern of repeating phases.
1) The first arm phase.
Most groups, including ours, start with the right arm of the boss. This is the arm on the 3rd quadrant of the map.
When the fight starts, make sure to get on this 3rd quadrant and always stay on this 3rd quadrant. Going on the 2nd quadrant can cause the other arm to phase in.
Conjured Amalgamate will raise up his arm and slam it down after a few seconds. Try to dodge this slam.
The arm stays down for 15 seconds, in which everyone needs to dps the arm.
After 15 seconds, CA lifts his arm up again and will smash it down after another few seconds. This is also when a group of conjured swords spawns around us.
These need to be killed. If you pick up a "sword pickup", keep it untill the next adds spawn.
CA smashes his arm down (dodge this again) and it can be dpsed for another 15 seconds or so.
After these 15 seconds, he will once again raise his arm and the conjured shields will spawn around us. These need to be cc'd before they can be killed.
Focus on the shields untill the arm comes down again. If you pick up any shield pickups, keep them.
CA smashes his arm down again (dodge this again) and it can be dpsed for another 15 seconds. This is also when people with a "sword pickup" need to use their special action to hit both the arm and any remaining shields.
After these 15 seconds, he will raise his arm again and do the thunderclap ability.
CA claps his hands and everyone will take massive damage. Everyone must stack on top of each other and the people with shield pickups must use it now. If not used, the group will die.
CA will smash his arm down again (dodge this again) and it can be dpsed for anotehr 15 seconds. If the arm can't be killed in this phase then the dps is really bad and needs to be better. Ideally we want the arm broken before the thunderclap, but it's fine to use an extra phase.
In short: arm -> swords -> arm -> shields -> arm -> thunderclap -> arm.
2) The first dps/collection phase.
After the first arm died, the entire group goes to the middle (arrow marker) and starts dpsing the boss, except collectors "sword 1" and "shield 1".
A lot of orbs come flying in towards CA. Important of these are green orbs with a vertical white line (sword orbs) and green orbs with a white circle around (shield orbs).
The sword orbs come in from quadrant 1 to quadrant 4, the shield orbs come in from quadrant 4 to quadrant 1.
Sword 1 must run to quadrant 1-2 and collect the sword orbs as they come in. Stay at the inner circle of the arena or you will not be able to run fast enough.
Shield 1 must do the same, but starting on quadrant 3-4.
When "sword 1" and "shield 1" cross the middle, "sword 2" and "shield 2" take over and continue the collection while sword 1 and shield 1 start attacking the boss.
If a sword gets through to the boss, the boss will deal more damage.
If a shield gets through to the boss, the boss will become invulnerable untill a sword ability is used.
Sword 1 can use his/her sword special action on the boss for etra damage and perhaps break the shield if it appeared.
Shield 1 must keep his shield for now.
After the collection phrase ends, everyone stays stacked on the arrow marker and dpses the boss.
Sword 2 can also use his sword on the boss for extra damage.
A rubble wall will move over the area, going from quadrant 4 to quadrant 1 (from right to left.)
When it is about to pass the group, "shield 1" must use his special action to protect the group. Otherwise we wipe.
Shield 2's ability is -technically- not needed so it can be used as a backup for shield 1, or kept for the next phase, if a "tricky situation" pops up.
3) The second arm phase.
This phase is exactly the same as the first arm phase. The only differences are that it happens on quadrant 2 instead of 3, and instead of a thunderclap, the boss will make rubble fall down.
After this arm is destroyed, the next phase starts.
In short: arm -> swords -> arm -> shield -> arm -> rubble -> arm.
4) The second collection phase.
This phase is identical to the first collection phase. The only difference is that the rubble wall afterwards will go over us twice, first from left to right (quadrant 1->4) and then from right to left (quadrant 4 -> 1)
We can use both shield players to block the wall twice, but it is easier to move to the second marker (circle) instead. When the wall is about to hit the group, shield 1 can use his special action to block the wall in both directions.
Do not use the ability too early though. Remember to keep dpsing the boss during this.
Edit: it is possible that CA follows up this phase with another thunderclap, so it is important to keep shield 2 ready!
5) Third arm phase
Identical to the first arm phase.
6) Third collection phase
This is really the last moment to kill the boss, if not killed here then again the dps is lacking extremely hard.
With better damage output, the arms die with 3 or less slams and the boss dies within 2 collection phases.
Keep in mind that at least the shields must still be collected of the boss will get an invulnerability shield.